Dental impression-cup



(No Model R. A. DUNLAP. DENTAL IMPREISSION 0UP.

No. 583,848. Patented June 1 ,1897.

UNITED STATES PATENT Grimes.

ROBERT A. DUNLAP, OF CARROLLTON, OHIO.

DENTAL lMPRESSlON-CUP.

SPECIFICATION forming part of Letters Patent No. 583,848, dated June 1,1897.

Application filed April 1, 1897. Serial No. 630,284. (No model.)

T0 at whom it may concern.-

Be it known that 1, ROBERT A. DUNLAP, a citizen of the United States,residing at Carrollton, in the county of Carroll and State of Ohio, haveinvented certain new and useful Improvements in DentistsImpression-Cups; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention has relation to improvements in dental impression-cups; andthe object is to provide an impression-cup with a safety guard or shieldwhich shall prevent any surplus plaster from coming in contact with thesofter tissues of the mouth or palate, and consequently prevent thepossibility of even the smallest particle of the plaster slipping downthe throat.

To these ends the novelty consists in the construction, combination, andarrangement of the same, as will be hereinafter more fully described,and particularly pointed out in the claims.

In the accompanying drawings the same reference-characters indicate thesame parts of the invention.

Figure 1 is a perspective view of my improved dental impression-cup.Fig. 2 is a similar view showing the shield detached and removed a'shortdistance from the cup. Fig. 3 is a bottom plan view of the cup. Fig. 4is a transverse section through the cup and shield. Fig. 5is alongitudinal section of the same. Fig. 6 is an end elevation of theshield.

1 represents an ordinary dental impressioncup, and 2 represents theshield, the upper face 3 of which conforms to the configuration orcontour of the bottom of the cup contiguous to its inner transverse edge4, while the side flanges 5 5 of the shield extend upwardly and fitsnugly around the ends of the walls 6 6 of the cup, practically forminga continuation of the same.

7 represents the transverse wall or guard formed integral with theshield and extending across between the flanges 5 5, and its upper edge8 conforms in outline to the shape of that portion of the roof of themouth with which it comes in contact, and the edge itself issufficiently sharp and smooth to sufficiently indent the flesh withoutpain and form a shield or barrier to the plastic composition passingthis point of contact of the edge of the shield with the roof of themouth.

9 represents a leaf-spring having one end detachably though rigidlysecured to the under side of the cup by the thumb-screw and its bodyportion extending longitudinally in a corresponding groove 10 in thebottom face of the shield. The outer or free end of this springterminates in a right-angular lug 11, having a rearwardly projectingtooth 12, which engages a recess 13 in the outer face of the transversewall 7, and which not only serves to hold the shield in contact with thecup but also absolutely prevents its accidental displacement. At thesame time the spring 9, lying in the groove 10, prevents any lateraldisplacement of the shield with reference to the cup, and as the springengages the shield midway of its width it acts as a spring fulcrum-pointfor the shield to work on, thus allowing it to conform to the mouthwithout particular regard to the level position in which the cup may beheld. It will thus be seen that when the plaster or other plasticcomposition is placed in the cup and the cup ad- 3' usted to take theimpression the Wall 7 automatically adjusts itself to the roof of themouth and remains fixed there by the spring, while the cup is pressedfarther upward to secure the impression, and in this position it isabsolutely impossible for any of the composition to work past the wall,and if any surplus escape from the rear edge of the cup it will becaught and retained by the upper face 3 of the shield, so that aperfectly satisfactory impression is obtained without a particle of theplaster escaping or even coming in contact with the more delicate andsensitive portions of the mouth.

- Although I have specifically described the construction and relativearrangement of the several elements of my invention, I do not desire tobe confined to the same; as such changes or modifications may be made asclearly fall within the scope of myinvention without departing from thespirit thereof.

Having thus fully described my invention, what I claim as new anduseful, and desire to secure by Letters Paten t of the United States,

9 detachably secured thereto and provided at its free end with the lug11, having'a project- I5 ing tooth 12, with the independent shield 2,provided with the longitudinal groove 10 and recess 13, substantially asshown and described.

In testimony whereof I affix my signature :0 in presence of twowitnesses.

ROBERT A. DUNLAP.

Witnesses:

ROBERT E. MCDONALD, LILLIAN BRIOKER.

